The present invention is directed generally to a method and system for control of the vehicle dynamics of a vehicle train.
Vehicle-dynamics control methods rely on selective automatic actuation of an engine controller and/or of individual wheel brakes of the vehicle in order to prevent unsafe driving conditions, such as oversteering, understeering or skidding, or at least to reduce the consequences thereof. In the field of commercial vehicles, a technique known for a vehicle train comprising a tractor vehicle and a trailer vehicle is to provide a vehicle-dynamics control system in the tractor vehicle. In performing a vehicle-dynamics control method, this vehicle-dynamics control system also involves the trailer vehicle in the control process to the extent that, in certain driving situations, a preprogrammed brake-pressure command is transmitted to the trailer vehicle, for example via a trailer control valve or a data interface. Thus, in the identified driving situations, a braking effect by which the handling of the entire vehicle train can be stabilized is applied to the trailer vehicle in order to prevent, for example, jackknifing of the vehicle train or severe skidding.
On roadways with a relatively low coefficient of friction, the preprogrammed brake-pressure command may already lead under certain circumstances to an undesired reduction of the cornering forces on the wheels of the trailer vehicle, even before an anti-lock braking system in the trailer vehicle has time to respond. Maintenance of adequate cornering forces, however, is important for effective stabilization of the handling of the vehicle train.
It is desired to provide a vehicle-dynamics control method and system for a vehicle train that permits activation of the brake system of the trailer vehicle while at the same time avoiding an undesirably large reduction of the cornering forces on the wheels of the trailer vehicle.